scholarly journals Redistribution of H3K27me3 and acetylated histone H4 upon exposure to azacitidine and decitabine results in de-repression of the AML1/ETO target geneIL3

Epigenetics ◽  
2013 ◽  
Vol 9 (3) ◽  
pp. 387-395 ◽  
Author(s):  
Francesca Buchi ◽  
Erico Masala ◽  
Alessia Rossi ◽  
Ana Valencia ◽  
Elena Spinelli ◽  
...  
Keyword(s):  
Histone H4 ◽  
Acetylated Histone H4

Active transgenes in zebrafish are enriched in acetylated histone H4 and dynamically associate with RNA Pol II and splicing complexes

1999 ◽  
Vol 112 (7) ◽  
pp. 1045-1054 ◽  
Author(s):  
P. Collas ◽  
M.R. Liang ◽  
M. Vincent ◽  
P. Alestrom
Keyword(s):  
Transgene Expression ◽  
Functional Organization ◽  
Histone Deacetylation ◽  
Splicing Factors ◽  
Histone H4 ◽  
Rna Pol Ii ◽  
Pol Ii ◽  
Acetylated Histone H4 ◽  
Co Precipitation

We have investigated the functional organization of active and silent integrated luciferase transgenes in zebrafish, with the aim of accounting for the variegation of transgene expression in this species. We demonstrate the enrichment of transcriptionally active transgenes in acetylated histone H4 and the dynamic association of the transgenes with splicing factor SC35 and RNA Pol II. Analysis of interphase nuclei and extended chromatin fibers by immunofluorescence and in situ hybridization reveals a co-localization of transgenes with acetylated H4 in luciferase-expressing animals only. Enrichment of expressed transgenes in acetylated H4 is further demonstrated by their co-precipitation from chromatin using anti-acetylated H4 antibodies. Little correlation exists, however, between the level of histone acetylation and the degree of transgene expression. In transgene-expressing zebrafish, most transgenes co-localize with Pol II and SC35, whereas no such association occurs in non-expressing individuals. Inhibition of Pol II abolishes transgene expression and disrupts association of transgenes with SC35, although inactivated transgenes remains enriched in acetylated histones. Exposure of embryos to the histone deacetylation inhibitor TSA induces expression of most silent transgenes. Chromatin containing activated transgenes becomes enriched in acetylated histones and the transgenes recruit SC35 and Pol II. The results demonstrate a correlation between H4 acetylation and transgene activity, and argue that active transgenes dynamically recruit splicing factors and Pol II. The data also suggest that dissociation of splicing factors from transgenes upon Pol II inhibition is not a consequence of changes in H4 acetylation.

scholarly journals Genome-Wide Relationships between TAF1 and Histone Acetyltransferases in Saccharomyces cerevisiae

2006 ◽  
Vol 26 (7) ◽  
pp. 2791-2802 ◽  
Author(s):  
Melissa Durant ◽  
B. Franklin Pugh
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Histone Acetylation ◽  
Rna Polymerase Ii ◽  
Histone Acetyltransferases ◽  
Histone H4 ◽  
Promoter Regions ◽  
Genome Wide ◽  
Acetylated Histone H4

ABSTRACT Histone acetylation regulates gene expression, yet the functional contributions of the numerous histone acetyltransferases (HATs) to gene expression and their relationships with each other remain largely unexplored. The central role of the putative HAT-containing TAF1 subunit of TFIID in gene expression raises the fundamental question as to what extent, if any, TAF1 contributes to acetylation in vivo and to what extent it is redundant with other HATs. Our findings herein do not support the basic tenet that TAF1 is a major HAT in Saccharomyces cerevisiae, nor do we find that TAF1 is functionally redundant with other HATs, including Gcn5, Elp3, Hat1, Hpa2, Sas3, and Esa1, which is in contrast to previous conclusions regarding Gcn5. Our findings do reveal that of these HATs, only Gcn5 and Esa1 contribute substantially to gene expression genome wide. Interestingly, histone acetylation at promoter regions throughout the genome does not require TAF1 or RNA polymerase II, indicating that most acetylation is likely to precede transcription and not depend upon it. TAF1 function has been linked to Bdf1, which binds TFIID and acetylated histone H4 tails, but no linkage between TAF1 and the H4 HAT Esa1 has been established. Here, we present evidence for such a linkage through Bdf1.

Targeted histone H4 acetylation via phosphoinositide 3-kinase- and p70s6-kinase-dependent pathways inhibits iNOS induction in mesangial cells

2006 ◽  
Vol 290 (2) ◽  
pp. F496-F502 ◽  
Author(s):  
Zhiyuan Yu ◽  
Bruce C. Kone
Keyword(s):  
Mesangial Cells ◽  
Histone H4 ◽  
P70s6 Kinase ◽  
Inos Gene ◽  
Histone H4 Acetylation ◽  
Inos Promoter ◽  
Acetylated Histone H4 ◽  
Phosphoinositide 3 Kinase ◽  
Kinase Pathway ◽  
Inos Induction

The inducible nitric oxide synthase (iNOS) gene plays an important role in the response to and propagation of injury in glomerular mesangial cells. Although several cis and trans regulatory factors have been characterized, epigenetic regulation of the iNOS gene has not been considered extensively. In this report, we explored the role of histone acetylation in interleukin (IL)-1β-mediated iNOS induction in cultured murine mesangial cells. Treatment of cells with the histone deacetylase inhibitor trichostatin A (TSA, 200 nM) resulted in a time-dependent, selective increase in histone H4 acetylation. TSA treatment of cells stably transfected with an iNOS promoter-luciferase construct inhibited IL-1β induction of endogenous nitric oxide and iNOS protein production and iNOS promoter-luciferase activity. Chromatin immunoprecipitation assays revealed that, under basal conditions, acetylated histone H4 associated with the region −978 to −710 of the iNOS promoter, a region rich in gene control elements and that IL-1β significantly increased this binding, which was further accentuated by cotreatment with TSA. Blockade of the phosphoinositide 3-kinase pathway with LY-294002 or the p70s6-kinase pathway with rapamycin in the presence of TSA and IL-1β inhibited 389Thr phosphorylation of p70s6 kinase, promoted binding of acetylated histone H4 to the iNOS promoter, and further suppressed iNOS protein expression and iNOS promoter activity. Thus TSA diminishes IL-1β-induced iNOS transcription through phosphoinositide 3-kinase- and p70s6 kinase-dependent pathways that increase site-specific histone H4 acetylation at the −978 to −710 region of the iNOS promoter. This novel epigenetic control mechanism extends the network of regulatory controls governing NO production in mesangial cells.

Tomographic distribution of acetylated histone H4 in plant chromosomes, nuclei and nucleoli

Chromosoma ◽  
1996 ◽  
Vol 105 (5) ◽  
pp. 293-302
Author(s):  
Shinya Idei ◽  
Katsuhiko Kondo ◽  
Bryan M. Turner ◽  
Kiichi Fukui
Keyword(s):  
Histone H4 ◽  
Plant Chromosomes ◽  
Acetylated Histone H4

scholarly journals Binding of a Monoclonal Antibody to Sporozoites of Sarcocystis singaporensis Enhances Escape from the Parasitophorous Vacuole, Which Is Necessary for Intracellular Development

2001 ◽  
Vol 69 (10) ◽  
pp. 6475-6482 ◽  
Author(s):  
T. Jäkel ◽  
E. Wallstein ◽  
F. Müncheberg ◽  
C. Archer-Baumann ◽  
B. Weingarten ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Specific Binding ◽  
Parasitophorous Vacuole ◽  
Intracellular Localization ◽  
Ultrastructural Analysis ◽  
Early Gene ◽  
Histone H4 ◽  
Acetylated Histone H4 ◽  
Development In Vitro

ABSTRACT Early intracellular development in vitro of the cyst-forming protozoon Sarcocystis singaporensis and the influence of a monoclonal antibody on invasion, intracellular localization, and development of sporozoites were studied. As revealed by immunofluorescence using parasite-specific antibodies which labeled the parasitophorous vacuole membrane (PVM) and by ultrastructural analysis, sporozoites invaded pneumonocytes of the rat via formation of a parasitophorous vacuole (PV). About half of the sporozoites left this compartment within the first 8 h postinfection to enter the host cell cytosol. By semiquantitative analysis of acetyl-histone H4 expression of sporozoites, a marker linked to early gene expression of eukaryotic cells, we show (supported by ultrastructural analysis) that escape from the PV appears to be necessary for early intracellular development. More than 90% of sporozoites located in the cytosol expressed high levels of acetylated histone H4 in the nucleus, whereas only a quarter of the intravacuolar sporozoites exhibited a similar signal. As revealed by ultrastructural analysis, young schizonts all resided in the cytosol. Specific binding of a monoclonal antibody (11D5/H3) to sporozoites before invasion significantly enhanced their escape from the PV, whereas cell invasion itself remained unaffected. The antibody actually increased proliferation of the parasites in vitro, providing a further link between residence in the cytosol and successful intracellular development. Monoclonal antibody 11D5/H3 precipitated a major 58-kDa antigen from oocyst-sporocyst extracts and reacted with the cytoplasm and the surface of sporozoites in immunofluorescence assays. Collectively, the observed antibody-parasite interaction suggests the existence of a signaling event that influences intracellular development of Sarcocystis.

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